Possessing greater motivation and a sense of purpose in life may help stave off the effects of Alzheimer's disease, a new study suggests.

"Our study showed that people who reported greater purpose in life exhibited better cognition than those with less purpose in life even as plaques and tangles accumulated in their brains," lead researcher Dr. Patricia Boyle of Rush University Medical Centre in Chicago, said in a statement.

"These findings suggest that purpose in life protects against the harmful effects of plaques and tangles on memory and other thinking abilities. This is encouraging and suggests that engaging in meaningful and purposeful activities promotes cognitive health in old age," Boyle added.

The study, published in the journal Archives of General Psychiatry, consisted of 246 participants who did not have dementia and who had later died and underwent a brain autopsy.

All participants had received a yearly clinical evaluation for up to 10 years, consisting of detailed cognitive testing and neurological exams and subjects were asked to answer questions about their purpose in life or the degree to which they derive meaning from their life’s experiences.

While plaques and tangles, which disrupt memory and other cognitive functions, are very common among Alzheimer’s patients, recent research suggest that they also accumulate in many older adults who don’t have dementia.

Researchers quantified brain plaques and tangles after death, and found that even though an accumulation of plaques and tangles were found in the brains participants who exhibited a greater purpose in life show, they exhibited a slower rate of cognitive decline, compared to other subjects.

Boyle and her team noted that while a great proportion of Alzheimer’s research is dedicated to identifying ways to prevent or limit the accumulation of plaques and tangles in the brain, until effective preventative therapies are found, research on ways to minimize the impact of plaques and tangles on cognition are also urgently needed.

"These studies are challenging because many factors influence cognition and research studies often lack the brain specimen data needed to quantify Alzheimer's changes in the brain," Boyle said.

"Identifying factors that promote cognitive health even as plaques and tangles accumulate will help combat the already large and rapidly increasing public health challenge posed by Alzheimer's disease," she added.